Determining socio-technical systems requirements: experiences with generating and walking through scenarios

Scenarios are effective for discovering requirements, but we still do not understand what types of scenario and which walkthrough techniques are most effective. We report the application of one scenario approach - CREWS-SAVRE - to discover requirements for naval and air traffic management systems with BAE Systems and Eurocontrol respectively. Results from these experiences are used to investigate important questions about the effectiveness of structured scenario walkthroughs and the level of domain-specificity most beneficial to the discovery of requirements. Lessons learned suggest that systematic walkthroughs of simple scenarios that do not contain excessive domain knowledge are more effective for discovering system requirements. This provides the reader with simple-to-use guidelines for scenario-based requirements discovery.